The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
An engine combusts air and fuel to generate torque. Air flows into the engine through an air induction system. Fuel is provided by one or more fuel injectors. Exhaust resulting from combustion is expelled from the engine to an exhaust system. A mass air flow (MAF) sensor measures a mass flow rate of air into the air induction system.
An exhaust gas recirculation (EGR) system re-circulates exhaust back to the air induction system. For exhaust to flow back to the air induction system, a pressure within the exhaust system must be greater than a pressure within the air induction system. The EGR system maybe controlled to provide a target mixture of exhaust, air, and fuel to each cylinder. The engine may not operate as intended when the target mix is not maintained. Additionally, the presence of a fault in the EGR system may need to be identified, for example, for an on-board diagnostic (OBD) reason and/or one or more other suitable reasons.